Hi,

While transmitting the classmark or any message from mobile on SDCCH during a call, does it transmit on the frequency we get after converting the ARFCN or is there a slight variation ?

I don't get this, what do you mean by 'converting the ARFCN'?

There are two (as I know) possible types of call assignment:

- Early Assignment, when the network allocates TCH/F or TCH/H right after getting RACH-request from a mobile phone. The frequency (or a set of them) is indicated in the Immediate Assignment message.

- Late Assignment, when the network allocates an SDCCH channel first, where a mobile phone indicates a connection reason (Paging Response or Service Request) and also indicates the classmark. Then the network eventually sends the Assignment Command message, where just like in Immediate Assignment a new channel data (both FDMA and TDMA) are described.

BTW: please choose a proper subject for this thread and don't interfere with the existing one because they are unrelated.

With best regards, Vadim Yanitskiy.